In recent years, for mobile devices, Specific Absorption Rate (SAR) values have been controlled according to regulations. According to one embodiment, when an electronic device is located in a weak-electric-field network, the electronic device can transmit a signal with transmission power of the maximum transmission power value. In this case, when the proximity of a user (or human body) to the electronic device or a grip on the electronic device by the user (or human body) is detected, the electronic device may back off the transmission power and may transmit a signal with transmission power of a transmission power value that is lower than the maximum transmission power value so that the absorption rate of electromagnetic waves caused by the electronic device does not exceed a regulated SAR value.